In a semiconductor factory, wafers as products are accommodated for each plural number into a wafer carrier (hereinafter referred to simply as “carrier”) and carried in this state to individual equipments in a manufacture line in a unit of a carrier by a carrier carrying system. As a carrier, an FOUP (Front Opening Unified Pod) is frequently used. A load port apparatus is mounted on an attaching face of a wall body of a semiconductor manufacturing apparatus (which may sometimes be hereinafter referred to merely as “manufacturing apparatus”) for receiving wafers in a unit of a carrier and carrying out processing for the wafers. The load port apparatus receives a carrier carried thereto from the carrier carrying system to the manufacturing apparatus and transfers the wafers accommodated in the carrier into the manufacturing apparatus. Further, the load port apparatus receives the wafers processed in the manufacturing apparatus and accommodates the wafers back into the carrier.
The load port apparatus is removable from the manufacturing apparatus. For example, for the object of cleaning of the inside of the manufacturing apparatus or of exchange or maintenance of various components in the manufacturing apparatus, the load port apparatus is frequently mounted on or removed from the manufacturing apparatus. Further, when the removed load port apparatus or another load port apparatus scheduled to be attached is to be moved, for example, a bogie truck is mounted at a lower portion of the load port apparatus to move the load port apparatus to a predetermined place. In order to carry out exchange or maintenance of various components in the manufacturing apparatus rapidly without stopping the carrier carrying system, it is necessary for removal and mounting of the load port apparatus to be carried out rapidly. Therefore, reduction of the removing and mounting time of the load port apparatus, particularly reduction of the mounting (attaching) time, is demanded strongly. Although normally 10 to 20 minutes are required for the mounting, attaching time of two to five minutes is demanded recently, and short attaching time is one of significant characteristics of the load port apparatus.
One of load port apparatus designed for reduction of the attaching time is, for example, such a load port apparatus L′ having an attaching apparatus A′ as disclosed in Patent Document 2. As shown in FIGS. 10(A) and 10(B), the attaching apparatus A′ of a lower side plate portion of the load port apparatus L′ is formed from a positioning plate 82 formed at a lower end portion of a mounting board 81 of the load port apparatus L′, a pair of positioning guides 83a and 83b secured to a lower portion of an attaching face 80 of a manufacturing apparatus E′, and a plate holder 84 sandwiched between the positioning guides 83a and 83b for receiving the positioning plate 82. When the load port apparatus L′ is mounted on the attaching face 80, the positioning plate 82 is positioned by being inserted between the positioning guides 83a and 83b and supported by the plate holder 84. Further, the mounting board 81 contacts at a lower end face thereof with a lower bracket 85 to support the entire load port apparatus L′. In the case of the attaching apparatus A′, since the positioning plate 82 is in the form of a thin plate and also the space into which the positioning plate 82 is inserted is narrow, it is not easy to adjust and insert the positioning plate 82 between the positioning guides 83a and 83b and much time is required. Further, from the configuration that the positioning plate 82 is inserted, the width of the positioning plate 82 is smaller than the distance between the positioning guides 83a and 83b, and therefore, even if the positioning plate 82 is inserted, a small gap appears and complete positioning cannot be achieved. Further, even if positioning of the load port apparatus L′ can be carried out, since the entire load port apparatus L′ is supported by the lower bracket 85 in the form of a thin plate, the stability is low and, when the load port apparatus L′ is to be fastened to the attaching face 80 by means of screws, it must be held up carefully so that a lower end face of the mounting board 81 of the load port apparatus L′ may not be displaced from the lower bracket 85. It is to be noted that reference numeral 86 in the figure denotes a caster of the load port apparatus L′.    Patent Document 1: Japanese Patent Laid-Open No. 2000-332079    Patent Document 2: Japanese Patent Laid-Open No. 2001-345366